Cold, not the heat, is the biggest killer. For the last decade, Brits have been dying from the cold at the average rate of 29,000 excess deaths each winter. Compare this to the heatwave ten years ago, which claimed 15,000 lives in France and just 2,000 in Britain. In the ten years since, there has been no summer death spike at all. Excess winter deaths hit the poor harder than the rich for the obvious reason: they cannot afford heating. And it is not just those at risk who benefit from moderate warming. Global warming has so far cut heating bills more than it has raised cooling bills. If it resumes after its current 17-year hiatus, and if the energy efficiency of our homes improves, then at some point the cost of cooling probably will exceed the cost of heating — probably from about 2035, Prof Tol estimates.

The greatest benefit from climate change comes not from temperature change but from carbon dioxide itself. It is not pollution, but the raw material from which plants make carbohydrates and thence proteins and fats. As it is an extremely rare trace gas in the air — less than 0.04 per cent of the air on average — plants struggle to absorb enough of it. On a windless, sunny day, a field of corn can suck half the carbon dioxide out of the air. Commercial greenhouse operators therefore pump carbon dioxide into their greenhouses to raise plant growth rates. . . .